This undated image provided by Barr Pharmaceuticals Inc. on Wednesday, Aug. 22, 2007 shows the packaging for the "Plan B" pill. In the year since it was approved for over-the-counter sales, the morning-after pill has become a huge commercial success for its manufacturer, but its popularity and solid safety record haven't deterred critics from seeking to overturn the milestone ruling. The Food and Drug Administration declared on Aug. 24, 2006 that customers 18 and older should be able to buy it in pharmacies without a prescription. (AP Photo/Barr Pharmaceuticals Inc.)

Women wanting to prevent pregnancies after unprotected sex will be able Thursday to purchase the "morning-after" pill from the shelves of most pharmacies and drug stores without being queried about their age or having to wait in line at the pharmacy counter.

This simple relocation of the "Plan B One Step" pill — next to condoms, tampons and sanitary napkins, instead of behind pharmacy counters — represents the final step in a complex decade-long legal battle to make emergency contraception more readily available.

"It's a great advancement in women's health, being able to get access to birth control if unprotected sex has happened," Verrilli said. "The more options women have available — is always a good day."

Government officials sought to keep the "morning-after" pill age-restricted by only allowing young women age 17 and older to buy it, but dropped that fight in June after losing a long series of court battles. A federal judge ruled the government-imposed restrictions were "arbitrary, capricious and unreasonable."

In the past women in California had been able to purchase the pill without a prescription, but were forced to show identification at a pharmacy counter — a step that some said could intimidate young women, delaying access to a time-sensitive medication. Plan B, trademarked as Plan B One-Step, is similar to birth control pills, but concentrates hormones into a higher dose and is most effective the sooner it's taken.

The product's opponents, such as the Sacramento-based National Right To Life Committee and the pregnancy counseling centers Birthright, could not be reached for comment.

While some independent pharmacies are already rearranging their shelves, nationwide chains such as Walgreens, CVS and Safeway were planning to spend Wednesday night making the transition from pharmacy to shelf. Some Rite Aid stores are already offering the product in the family planning aisle.

Kirsten "Jennifer" Voss, chief of OB/GYN for Marin General Hospital, said the pill's main ingredient levonorgestrel can be found in birth control pills and has proven to be a safe, effective medication for many years.

"The side effects of using something like Plan B are very minimal, mainly nausea, which only occurs in about 4 percent of users," Voss said.

She said the pill has a 90 percent chance of being successful at preventing an unwanted pregnancy if taken within 72 hours after sexual intercourse. It can even be taken up to 120 hours after sex, but the rate of efficacy drops to 60 percent.

Voss said there's a large number of women who don't know the pill exists and that educating them about their options is key. She said there's a lot of misinformation about how the pill works.

"It's not an abortion pill. It helps prevent a pregnancy before it occurs," Voss said.

She said the pill can stop or delay the release of an egg from the ovaries, prevent fertilization of an egg and/or prevent an egg from embedding itself in the lining of the uterus by altering the lining's composition.

Critics of the pill are concerned it might promote promiscuity or encourage women to only use the pill instead of other forms of contraception, but Voss said that's unlikely.

"Studies have shown that is an unfounded concern," Voss said.

Matthew Willis, Marin County public health officer, agreed.

"For people who are concerned this might lead to more careless sexual behavior, I think a woman seeking the morning-after pill is declaring that she cares. There's no evidence to suggest that this would become a casual routine after unsafe sex," Willis said.

Additionally, Verrilli said it's unlikely women will use the "morning-after" pill instead of birth control given one pill can cost $50 to $70. She said if anything, the high cost might pose a barrier for women needing emergency contraception. Planned Parenthood clinics provide the pill for patients for free or at a low cost.

The drug's price is unlikely to drop until 2016, when Teva Pharmaceutical Industries in Israel loses its exclusive marketing rights granted by the U.S. Food and Drug Administration.

Larry Meredith, director of the Marin County Department of Health and Human Services, said he believes Marin women will make the proper choice about using Plan B as it relates to their ideals and beliefs.

"I'm a strong believer that women should be in charge of their bodies and this is part of that picture. If they're concerned, they can now respond as they see fit," Meredith said.